ITA CRX electrical guru question...

I thought I might some advice from the forum:

At our TMS race 2 weeks ago I was able to run a total of 1/4 of a lap in qualifying and that was it. Not fun. Here's the problem:

Car runs fine after intial start up however after it gets hot (temp 170+) it loses spark after 4000 rpm then dies. No spark and can't restart until it cools down.

We tried the following: replace coil, ignitor- no change. replace distributor- no change. relace TP switch and connector on harness- no change. Replace ECU- no change.

There are various error codes including: 7(TP sensor) 8(TD sensor) 14(IAC sensor)

I am running out of ideas at this point. Anybody have a similar experience or thoughts?

Pete

Quote:

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Originally Posted by pavis

I thought I might some advice from the forum:

At our TMS race 2 weeks ago I was able to run a total of 1/4 of a lap in qualifying and that was it. Not fun. Here's the problem:

Car runs fine after intial start up however after it gets hot (temp 170+) it loses spark after 4000 rpm then dies. No spark and can't restart until it cools down.

We tried the following: replace coil, ignitor- no change. replace distributor- no change. relace TP switch and connector on harness- no change. Replace ECU- no change.

There are various error codes including: 7(TP sensor) 8(TD sensor) 14(IAC sensor)

I am running out of ideas at this point. Anybody have a similar experience or thoughts?

Pete

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Bad Ground?

check all three ground points for the motor, starting with the thermostat ground.

I would also check the ECT, engine coolant temp. sensor under the distributor. Once it sees about 170F ECU gets out of cold start settings.

On street cars I've see 3-4 threads about this problem this month and no real cure, but I was paying all that much attention. If I come across something I will post it up.

Quote:

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Originally Posted by pavis

We tried the following: replace coil, ignitor- no change.

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How much do you trust the ignitor you tried? The problem really, really sounds like a bad ignitor. I believe your CRX uses the same ignitor as my old OBD0 Integra and that thing is a piece of crap.

I would suggest trying another ignitor that is known to be good. Also, long term, think about switching to an aftermarket capacitive system. I have used MSD for 5+ years with no trouble (although I carry a spare of each ignition component since I don't trust electrical stuff).

I agree that it is possibly a ground issue. We've checked those and they appear to be ok. We also replaced the distibutor with a known good one (it was running a car in the paddock!). All good ideas... keep 'em coming.

Pete

Possibly Main Relay contacts need to be re-soldered?

Main relay is a definite possibility as someone already said. There was also a bulletin at one point for loose connections at igniter (would explain all the codes though). The fix was to replace the terminals that go onto the igniter terminals with new ones, in a pinch you could just try giving the connectors a little squeeze and putting them back on. Aside from that remove ground G101 (ground on Tstat housing) and actually give it a little scrub with sand papaer in case any corrosion or paint is between the ground eyelet and the Tstat housing. The TDC code is usually distributor related...did you make sure to install a known good distrbutor? I have seen the pickup coil in the distributors come apart frequently due to corrosion and/or bad bearings in the distributor.

It may be a stretch, but check your battery and distributor charge. The two times I had erratic power loss, each one was caused by low battery charge and low distributor charging (distributor wire one time, loose distributor belt another time). Given that it happens so quickly, it may not be the problem but it is easy enough to check.

Does the ECU remain on? (check engine light, etc...) if so then it is most likely not a PGMFI main relay issue.

maybe look at replacing the ECT sensor and investigate the temp switch on the intake side of the block. It is supposed to switch to GND to switch the cooling fans on/off but there could be a series of shorts somewhere, especially if your wiring has been heavily "modified" for whatever reason - I don't think that the ECU sees this signal btw. it's a stretch but it occurs at about 170°F so it is worth checking. look at the engine/car harness connectors, too. might be best to disconnect and insulate the wire to this sensor and see if the problem persists before digging into the wiring.

if you need elec system details I can help with a lot of the point-point connections and logic schematics.

looks like we've fixed it using the "start replacing parts" approach. We replaced the engine wiring harness and it appears to be fixed. Thanks everbody for the help!

Pete