I did sooo much work to this ca. It was a disaster when i got it. but i finally got it running very strong and was in the process of painting. i removed the radio to put it in my other 95 del sol but now the Si fuel pump doesn't energize. I replaced the fuel pump about 5 miles ago. no fuses are blown. I swapped out the grey relay under the dash behind the fuse box. I don't think that the radio removal has anything to do with the fuel pump not energizing but thought I'd mention it just in case. any suggestions?

 

I'm only getting 9v to the fuel pump. what's wrong?

 

ok, maybe this is my problem. the under the hood fuse box is totally corroded. can this be the cause of my fuel pump not energizing? New fuel pump and the car was running great then the fuel pump doesn't run and only 9v at the hot wire. what say you honda men?

 

Checking voltage at the fuel pump plug doesn't tell the whole story... your multi-meter doesn't have a load on the circuit. What brand of fuel pump did you purchase and where did you get it ?

 

it's a KEMSO.... I can easily reinstall the old pump which was working.

KEMSO 340LPH High Performance Fuel Pump "Replace Walbro 255LPH GSS342" #14

 

update: I adjusted the valves and fixed an intake leak and it ran great UNTIL it warmed-up. then it began bogging badly again. could it be the mass airflow sensor?

 

You don't have a mass airflow sensor... just a manifold absolute pressure (MAP) sensor. Re-check your valve adjustment... if it is good, let's consider some other possibilities:

I have never heard of that brand... but it cannot be considered a quality product for that kind of price. Regardless of the brand, that is a BIG fuel pump for a stock single-jingle... and chances are good that you have fuel pressures that are WAY higher than stock because of the sheer volume of fuel pushing through. I just put a similar sized fuel pump into my Del Sol in preparation for an engine swap... replacing a 190 lph Walbro. Once installed, it made 27psi more fuel pressure than the old 190, so I pulled the 340 and installed a 255. Pressures are only slightly higher than (5-6 psi) they were with the 190 lph, so I will run with that.

Also, you need a way to check the outputs from your IAT and ECT sensors. If these are reading crazy/odd values, it will make your car run poorly.

 

That makes sense because it runs great when cold and bad when hot so it's getting too much gas. I'll put the old (working) fuel pump back in and see if that solves the problem. I'm assuming that the IAT is good because it idles-up and down normally but if the fuel pump replacement doesn't solve the problem i'll replace it. I really appreciate your help. THANKS! i miss the good old carburetor days.

 

Those have been gone for a WHILE !!! LOL Fuel Injection isn't any harder... it is just different. Us old guys are simply resistant to change.

 

OK, sorry for the confusion but my 1.5 del sol S is what i'm working on right now that bogs BADLY but only when hot I replaced the high pressure pump with a normal pump and same exact problem. runs great when cold then as it gets hotting it starts running terrible. if I give it more than 1/3 throttle it just makes noise but doesn't go. If i let up on the gas it starts to go but then when it gets hot It barely makes it up my driveway. . I adjusted the valves but one is ticking so I'll adjust them again tomorrow. I'm going to adjust the timing too. can spark plugs foul when hot? could it be another sensor? what should I try next?
THANKS!

 

You need to see what the IAT, ECT and O2 fuel trims are. Otherwise, you are just throwing parts at it and that really isn't a solution. What about the possibility of a clogged/stopped up cat ?

 

I thought about a clogged cat because it rattles. thanks for reminding me about it. but why would it run fine cold and bad hot?