[Hahkay]

Engine Cranks but Won’t Start
I didn’t want to create a new thread, but after weeks of researching and troubleshooting, I am stumped. Every crank no start thread I could find invovled mpfi / b and zc swaps, and although they had some good info, they all came to similar solutions. I made a list to organize my thoughts on what could be causing the condition. I know it’s a bit unorganized and incomplete, which is why I wanted to post it here to get some more info on what’s going on / common part failures leading to no start conditions. My engine has spark, is making compression, and I’m checking for fuel today. I’ve tested main relay and all fuses. My next steps are to check engine timing and ignition timing.
Thank you

Links:
ignition timing
engine timing
enine timing (with images)

 

[jlicrx]

what codes are showing on the ECU? always the first thing to check

 

[Hahkay]

I forgot to check, thank you for reminding me! The ecu was throwing some codes earlier for cooling, with my y7 swap I forgot to wire up the fan switch connectors to the thermostat housing and the coolant temp to ecu sensor to the sender on the head. Once I get that done it should show me the right codes. Thank you again, I can’t believe I forgot that haha

 

[joelidge]

The ECU only needs the crank sensor (in the distributer) to start as this is used to time the engine. Temp sensors, O2, MAP, TPS, ect. are all used to manage the engine. If you have good spark and compression, it is either fuel or timing. The ECU codes are generally not going to be useful as the engine doesn't know if it is out of time.

Check the timing then spray some carb cleaner in the intake manifold and see if it attempts to crank and follow your steps to isolate the issue to a single system then a single component.

 

[Hahkay]

Thank you, I didn’t know whether or not it had an effect on fueling. I think I’ll still wire in the fan switch and ct sensors so I can idle it at temp once it runs. I’ll double check the timing tonight too.

I wasn’t able to work on my car yesterday because I was helping with my friend’s ‘90 sedan. It melted a distributor rotor, we put in a spare dizzy and it wouldn’t start, but had strong spark. After some trial and error we decided to check the injectors to see if they were firing, sure enough they weren’t. We poured some gas in the tb and it started right up but would die. We suspected a clogged fuel line or filter but after a few tries it started up again and held idle really well. Took it for a test drive and it had power and ran really smooth. I find it strange that injectors weren’t firing at all and then worked perfect after putting gas in the tb. Well anyways that’s what I’ll try next.

Thank you again for the help!

 

[Hahkay]

I did some troubleshooting today and came to a very surprising conclusion. Injectors are firing lots of fuel, spark is good, timing is good, so why won't it start? Welp, I didn't mention it here but I picked this up as someone else's project. I bought the car for $100 and engine for $600. Now why would I buy a y7 for $600? It was actually a good deal, it's freshly rebuilt with forged crank, forged stroker rods, vitara pistons, bored out, forged bearings, new gapped rings, block guard, all that jazz. Pretty much a brand spankin new $4k bottom end and a 160k mile stock y7 head. Well anyways the C:R is bumped up quite a bit. My 500 cca battery wouldn't cut it so I charged it and jumped it. Now it cranked over alright but it was still a little slow. I bench tested the starter a while ago and it nearly flew off of the table it was on, so I know the starter's good right? Wrong, well sort of. The starter can't turn over the motor fast enough to even get it to burn the mixture! Now I need to figure out how to turn the darn motor quick enough to get this thing going! Using an impact on the crank pulley bolt was suggested, however I don't have any power tools, and it's not a very permanent solution, even if the motor is easier to turn after break-in I'm thinking I'd need a stronger starter. So I'm wondering what you guys are thinking? Thanks for all the help again in this thread and the other one and I apologize for telling the whole story haha.

 

[mossin_90]

You do realize that unless that engine has an absurd high compression ratio it should turn smoothly right.

Given all grounds are good, and everything is good.

Either that or someone:
1.over torque something that is keeping the engine under a really strong friction problem.

2.Piston rings have the wrong clearance

3.Main and or Rod bearings are also too big and are dragging, scratching, rubbing...you get the idea.

4. Camshaft is also rubbing.

Nobody will sell a perfect engine with lots of $$ invested for a fraction of the cost unless there is something really wrong with it. Jmo

Bottom line is. You need to make sure every friction point inside the engine is not under too tight tolerances that would keep the engine from turning as designed.

If the engine is tight now, it will self destroy once it starts and heat makes it tighter..

 

[mossin_90]

I also forgott about transmission problems.
I had a similar problem. Turned out to be the pilot bearing.
I can't recall all details, other than even after replacing trust washers, the engine was still dragging, the clutch set was new, and replacing the new pilot bearing back with the old solved it.
Gl

 

[Hahkay]

I know the previous owner through my friend who built the engine for him. My friend was paid to build the engine for the previous owner, I don’t know too many of the specs but I was told it wasn’t super high compression and it has a stroker kit with gapped rings. He has experience rebuilding ford v8’s, and he also worked at a shop rebuilding sprint car engines. I want to believe that he built the engine properly but I do recognize that it could be the issue. I got it so cheap because the previous owner is absurdly idiotic, knows absolutely nothing mechanical nor does he have a desire to learn. He drove the b2 in the car into the ground, refusing to replace the blown head gasket. He started pulling the b2 and gave up, sold me the car before the new engine was finished. He’s also had 14 cars in one year.

I pulled the plugs to check that they were good and they made a good spark. While they were out I cranked the engine over and it spun a lot more freely. I didn’t hear any scraping or clunking or anything like that when the plug tubes were open. The transmission I’m using is an 88 crx 5 speed from the junkyard, and I replaced with a full clutch kit. The old pilot bearing was really shot, and the new one seemed good. Do you think I should tear down the engine to check clearances? It seems like the only option left although I’d prefer not to for the reason that I haven’t had much experience with engine internals. I still have a lot to learn, I really appreciate all the advice.

I was bumping over the engine to check that the rotor was aligned with the right plug wire port on the dizzy, and it fired once. The timing was set full advance through the distributor, I ended up killing the battery before it would fire again. This seems really strange to me, it wouldn’t fire with starter fluid, only when the injectors fired normally. Should I try spraying starter fluid in through the plug tubes? I was also considering renting a compression tester from an auto parts shop, but I heard that they get stuck and read wrong.

 

[Hahkay]

Update:
I was bumping over the engine again and it fired. I was unsure of what was causing this behavior. I crank and crank and nothing, but it fires while bumping it over. I jump the car and measure battery voltage while cranking and sure enough it’s in the 9’s. So I charge the battery and it won’t take anything over 50%. Ive charged it at oreillys about 5 times and each time they test they say it’s good. Well anyways I’m going to buy a new battery. I guess I learned to do my own testing instead of bringing it to an auto parts store.

 

[msc]

If you have any questions about the block health ask some questions of the builder since you know him. Did he plastiguage the bearings? Did he use the factory service manual and perform all the inspections that Honda calls for? Sounds like he has some experience but just how professional is he.

Consider the possibility that your flooding. If this is the case you would have a heavy gas smell at the tailpipe and gas on the plugs after extensive cranking. With an aging DPFI system the injector seals can go bad and leak gas from the fuel rail directly to the intake manifold. This is the O-rings around the injector not the internal seals of the injector.

I would hang onto the battery, it probably has plenty of life left in it. I’m not clear on what your saying about the battery only taking 50% when charging. The information that chargers provide is often not very clear. To know if it’s good or bad requires seeing how that charger performs on both new and tired batteries of similar capacity to the small battery in a CRX. The parts store would have done a pulse load test with an idiot proof tester. If it says the battery is OK it has some life left in it. The next more extensive test would be to use a carbon pile tester and watch the voltage with 100+ amp sustained load.

Where exactly did you measure the battery voltage while cranking? You need to measure on the battery posts to see exactly what the battery voltage is. Low voltage on the battery terminals could be telling you the posts and terminals need cleaning.

Mike

 

[Hahkay]

I know he used plastigage, but I don't think he had a service manual. I know he used honda tech forum posts and the internet to find specs. The motor was pulled from a running, 160k mile '96 hatch.

I do think there is too much fueling going on. I pulled the plugs to clean them, and after maybe 2 mins of spaced out cranking, I checked #2 plug, it was fouled. I'll definitely inspect those injectors. It could also be due to the starting fluid I sprayed to rule out a fueling issue. While I was inspecting the plugs, I found one of the diodes was cracked, I'm ordering some platinum ngks to replace them. I talked to my friend who built the engine and he said the plugs weren't replaced.

The charger I borrowed was showing it would charge to 50% on its charging dial. After a whole night of charging it's cranking the engine over quite fast. It's a really small battery though, a 500cca with 80 reserve. I went to my local junkyard to get a battery and they were all out. And the parts store wouldn't warranty the battery because the previous owner didn't use his phone number when he bought it, so I didn't end up buying a new one.

I tested voltage directly at the battery terminals with a voltmeter. The terminal posts are shiny and the cable terminals and cable wires are new. I also cleaned all grounds, added dielectric grease, and checked for continuity everywhere there should be ground.

I'm thinking that the battery isn't able to supply enough voltage to all systems, resulting in a bad spark. When I was checking spark, I only bumped over the engine. The only 2 times the engine actually fired. I think that the quick cranks were able to supply enough power to the plug it was firing at once to get it to pop. While I crank it over normally I can hear the exhaust, but there are no pops, just a whoosh of air (I don't have an exhaust yet, just headers that exit right before the cat would be).

Thank you

 

[msc]

The fact that it cranks plenty fast after a good charge tells you the battery is fine. Lead acid batteries take 8 hours for a good charge and up to 24 hours to fully top off.

As I said the meters on many chargers don’t provide the most useful information. An overnight charge made the battery much happier, that’s about all you need to know.

If your able to crank the engine over you have plenty of power to run the ECU and make spark. These are automotive components that are designed to handle the voltage sag of starting as well as substantial spikes.

If you pull the injectors you will defiantly want to replace the O-rings or you will likely have leaks. The nature of old rubber seals is that if left alone they may continue to hold but if disturbed they probably are not soft enough to reseal.

I have no idea what you mean by cracked diode on the spark plug, perhaps you mean the insulator. Either way a fresh set of plugs is in order.

I can’t think of any reason the DPFI system would not run a moderately built engine but when you get this running you will want to look into an MPFI conversion. The DPFI system will drastically limit the performance potential of the engine.

How do the head lights look? If they are very dim you probably have a bad body ground connection. Another indicator of a bad body ground would be if the heater blower does not move much air. The stock battery ground cable has a mid point connection to the body that is often overlooked when replacing the cable.

BTW your CRX only has one header or perhaps the stock cast manifold. A V8 engine with it’s two heads can have two headers, often called a set of headers.

Mike

 

[Hahkay]

Sorry for all the mistakes, I bought this car with 0 experience and have been trying to learn everything over the past year.

Im glad to know the battery is ok. So I’m guessing it’s the fouled and old plugs causing weak spark? I forgot to mention, when I went to the parts store I rented out a compression tester. It had the hose blow off of the fitting and it got stuck. It screwed up my threads, but I managed to get the plug back in without damaging it’s threads. I’m wondering if it’s cranking so much faster because air is getting out of the plug tube. I’ll check to make sure tonight.

I think I’ll go buy an o-ring kit tonight. I see no reason in not checking the injectors and replacing them even if they are “good enough”.

I just checked a diagram and what I meant to say was the center electrode, thank you for correcting me, they arrive Thursday.

I’m not really that interested in performance yet, but I’m sure once I run dpfi for a good while I’ll be itching to swap. Also I think I need to research more on chip tuning before I mpfi swap because of the difference in ignition timing on the maps and the lack of a factory y7 map for obd1 tuning. My friend gave me a non-chipped pr4-a11 ecu and some other obd1 b series parts. I still need to get all the d series parts though. He also gave me a lot of guages, I need to get those in (oil pressure, tachometer, wideband lambda, oil temp).

The headlights look good! Although low beams only light up the right half of the headlamp, I’m not sure if this is normal. High beams light up the other half. Both are very bright. I bought the negative cable that grounds to both body and transmission. I also replaced the engine to body ground with a good one I found at the junkyard. However, the ground wire that usually goes to thermostat was moved to where the vac line holder bolts on. I checked continuity from the ground to engine and thermostat and it passed, the ground has a few wires in it, and I didn’t want to screw it up by extending them.

Thanks for the info, I didn’t realize I was saying it wrong this whole time haha. It’s a $60 header from ebay, since I needed a y8 one to clear the oil pan.